1. Field of the Invention
The present invention relates generally to an electronic apparatus, such as a foldable portable terminal apparatus, and more particularly, to an electronic apparatus having a display side case unit with a rotation function, a display control method for the electronic apparatus, a display control program for the electronic apparatus, and a recording medium.
2. Description of the Related Art
An electronic apparatus, such as a portable terminal apparatus, can be folded into a compact form when carried around if a case unit at the operation unit side and a case unit at the display unit side of the apparatus are openable and closable via a hinge. Besides, the electronic apparatus can be used with its display unit set in a vertically elongated form or a horizontally elongated form if the case unit having the display unit of a vertically elongated form is rotatable.
Japanese Patent Application Laid-Open Publication No. 2003-319043 discloses an apparatus related to such a portable terminal apparatus as described above, which has a folding function and the display side case unit with a rotation function. The disclosed apparatus includes an upper unit and a lower unit that are coupled to be openable and closable via a hinge, and the upper unit has a support unit and a display unit arranged in such a way that the display unit is rotatable and slidable relative to the support unit through a rotation/slide mechanism (ABSTRACT, claim 3, FIG. 4, etc.).
According to the conventional structure (Japanese Patent Application Laid-Open Publication No. 2003-319043) allowing the display unit of the display side case unit to be manipulated from a state of vertical elongation into a state of horizontal elongation or from the state of horizontal elongation into the state of vertical elongation, the display side case unit is shaped into an oblong corresponding to the shape of the display unit. Because of this, when the display unit is kept in the state of vertical elongation in normal time, rotating the display side case unit from the state of vertical elongation into the state of horizontal elongation creates an unnecessary gap between the horizontally elongated display unit and the operation unit. When the display unit is kept in the state of horizontal elongation in normal time, on the other hand, the rotation of the display side case unit becomes difficult. Solving this problem requires simultaneous use of a rotation function and a slide function in such a way that the unnecessary gap resulting from the rotation from the state of vertical elongation into the state of horizontal elongation is eliminated by moving the display side case unit toward the operation side case unit to bring both units closer to each other, using the slide function. This needs a complicated mechanism and operation therefore. Providing such a mechanism leads to poor operability, complicated rotation and slide mechanisms, and disadvantageous manufacturing costs.
With respect to the above requirement and problem, Japanese Patent Application Laid-Open Publication No. 2003-319043 offers no disclosure and suggestion including a structure that is a solution to the requirement and problem.